/*
 * Copyright (c) 2007 innoSysTec (R) GmbH, Germany. All rights reserved.
 * Original author: Edmund Wagner
 * Creation date: 05.06.2007
 *
 * Source: $HeadURL$
 * Last changed: $LastChangedDate$
 * 
 * the unrar licence applies to all junrar source and binary distributions 
 * you are not allowed to use this source to re-create the RAR compression algorithm
 * 
 * Here some html entities which can be used for escaping javadoc tags:
 * "&":  "&#038;" or "&amp;"
 * "<":  "&#060;" or "&lt;"
 * ">":  "&#062;" or "&gt;"
 * "@":  "&#064;" 
 */
package com.github.junrar.unpack.ppm;

import com.github.junrar.io.Raw;

/**
 * DOCUMENT ME
 * 
 * @author $LastChangedBy$
 * @version $LastChangedRevision$
 */
public class RarMemBlock extends Pointer
 {

  public static final int size = 12;

  private int stamp, NU;

  private int next, prev; // Pointer RarMemBlock

  public RarMemBlock(byte[] mem)
   {
    super(mem);
   }

  public void insertAt(RarMemBlock p)
   {
    RarMemBlock temp = new RarMemBlock(mem);
    setPrev(p.getAddress());
    temp.setAddress(getPrev());
    setNext(temp.getNext());// prev.getNext();
    temp.setNext(this);// prev.setNext(this);
    temp.setAddress(getNext());
    temp.setPrev(this);// next.setPrev(this);
   }

  public void remove()
   {
    RarMemBlock temp = new RarMemBlock(mem);
    temp.setAddress(getPrev());
    temp.setNext(getNext());// prev.setNext(next);
    temp.setAddress(getNext());
    temp.setPrev(getPrev());// next.setPrev(prev);
    // next = -1;
    // prev = -1;
   }

  public int getNext()
   {
    if (mem != null)
     {
      next = Raw.readIntLittleEndian(mem, pos + 4);
     }
    return next;
   }

  public void setNext(RarMemBlock next)
   {
    setNext(next.getAddress());
   }

  public void setNext(int next)
   {
    this.next = next;
    if (mem != null)
     {
      Raw.writeIntLittleEndian(mem, pos + 4, next);
     }
   }

  public int getNU()
   {
    if (mem != null)
     {
      NU = Raw.readShortLittleEndian(mem, pos + 2) & 0xffff;
     }
    return NU;
   }

  public void setNU(int nu)
   {
    NU = nu & 0xffff;
    if (mem != null)
     {
      Raw.writeShortLittleEndian(mem, pos + 2, (short) nu);
     }
   }

  public int getPrev()
   {
    if (mem != null)
     {
      prev = Raw.readIntLittleEndian(mem, pos + 8);
     }
    return prev;
   }

  public void setPrev(RarMemBlock prev)
   {
    setPrev(prev.getAddress());
   }

  public void setPrev(int prev)
   {
    this.prev = prev;
    if (mem != null)
     {
      Raw.writeIntLittleEndian(mem, pos + 8, prev);
     }
   }

  public int getStamp()
   {
    if (mem != null)
     {
      stamp = Raw.readShortLittleEndian(mem, pos) & 0xffff;
     }
    return stamp;
   }

  public void setStamp(int stamp)
   {
    this.stamp = stamp;
    if (mem != null)
     {
      Raw.writeShortLittleEndian(mem, pos, (short) stamp);
     }
   }
 }
